Improvement in knife-sharpeners



tanta @Swat pandemia `Letters Patent No. 103,113,4datecl May 17, 1870.

` IMPROVEMENT IN KNIFE-SHARPENERS `The Schedule referred tem these Letters Patent and making part of theeame To all persons to whom'these presents may come:

Be it known that I, PHINEAS M.' WITHINGToN, of Stoughton, in `the county of Norfolkand State of Massachusetts, have invented a new and useful 'Improve` ment inA KnifegStrops, or` Shave-Sharpeners; and do hereby declare the .same to be described as follows, reference being had to the accompanying drawings, of

Figure 1 denotes an 4edge viewof one of my improved Sharpeners, in'which the sharpening'slu'faces are convex in longitudinal directions only;

a Figure 2 denotes an edge view; and

v being a vnarrow strip of" wood of equal orabout ,equal thickness and width throughout, except at the part b, which is t 'constitute the handle, orpart to be grasped byA a person while .using the Sharpener.

'The opposite sides of the Sharpener, i (or one of them only ifdesirab1e,) areto be covered with "a layer,

B, of a compositicncomposedof. glue or cement, 'and `emery or any other materiallor materials generally' used to formjystony o'r grit-ty compound,capable of being used for 'sharpening aknife or tool, when rubbed or drawn over and upon its surface. v

Instead of 4making the layer B of equal thickness throughout, as heretofore, I curve it, or form it convex from end to end, asshown in iigrl, or from end Vto end and vedgeto edge, as shown in gs.l 2 and 3, in `which case I use no more of the material than would be generally necessary, were it to be of an eventhiokness throughout..

In Figure 4, I have represented a-sharpening implev ment of the ordinary kind, as made with the emery composition C, of even thickness on the-side of the body B, and I have exhibited, Aby the dotted line a b c ll'e, the form in which the same amount of material may be thrown by my plan of curving or making conrex the outer or sharpening smface. In other words, the rectangle C, or f g e, is equal in area to the arched gures t a b c al e la.. A

When using the sharpening implement, the wear is mostly at or near its middle, or from b to d, consequently, by having the increased thickness b e d h b, all suchA would have to be worn down before the part C would generally become worn. v

'lhlis it willl be seen that, by forming the composition with a convex surface, described, the Sharpener will last much longer, and beside this, it is found that in some incidents itis much better so made than to be Hat. y

I therefore claim as a new manufacture- A tool-sharpener of the improved kinddescribed, that is, as composed of a wooden body and a mass of emery or grinding-composition, cemented or fixed thereto, and as having the grinding-surface of such composition made convex from end to end, or from end to end and transversely, as hereinbef'ore explained.

' PHINEAS M. WI'lHlNGTON.

Witnesses:

R. H. EDDY, y i .S. N. PIPER-` 

